Alan Taylor, who runs the photojournalism blog In Focus, put together a fascinating series that showcases a variety of underground scenes that most of us have never seen. The set proves to be a great reminder of just how awesome our planet really is.

"We excavate to find both literal and cultural treasures, digging mines and unearthing archaeological discoveries," Taylor explains. "We use caverns for stable storage, for entertainment, and for an effective shelter from natural and man-made disasters. And as the planet's surface becomes ever more crowded, and national borders are closed, tunnels provide pathways for our vehicles and for smugglers of every kind."